When computer systems are arranged in a network, security of data transferred between the computer systems can be of considerable concern, especially when the data is sensitive and/or proprietary. Specific security concerns may depend on the type(s) of network used (e.g., wireless, point-to-point, Ethernet, etc.), the type(s) of computer systems in the network (e.g., servers, workstations, mobile devices, integrated devices, etc.), and/or the types of applications executing on the computer systems (e.g., web servers, terminal servers, peer-to-peer applications, email servers, etc.). Those skilled in the art will appreciate that many different security concerns may affect security requirements in a computer network.
Security measures may be implemented from the physical layer all the way up to the application layer of the network. For example, at the physical layer, dedicated physical connections clearly provide stronger security than unencrypted wireless networks. Many of the network layers allow for some form of data encryption, which may be used to secure data regardless of the security provided by lower layers. Further, security may be implemented using packet filtering, firewalls, Virtual Private Networks (VPN), Secure Socket Layer (SSL), Wi-Fi Protected Access (WPA), antivirus suites, any other type of security feature, or any combination thereof. As noted above, the specific security features used may depend on many different security concerns.
One example of a security concern arises when three or more computer systems are connected in a network. In such arrangements, data sent by a first computer system may pass through a second computer system en route to a third computer system. If the second computer system is executing malicious code and the data is not adequately secured, the malicious code may be able to intercept the data and access its contents. This type of security concern is particularly relevant when the route between the first computer system and the second computer system is non-trusted.